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Orbi RBR40 kernel panics

someuser2
Aspirant

Orbi RBR40 kernel panics

My Orbi RBR40 randomly reboots several times a day. The debug logs indicate that this is caused by a kernel panic:

<0>Kernel panic - not syncing: Fatal exception in interrupt
<4>@@@@@@@@@ DNI Kernel panic @@@@@@@@@@
3 <0>3ea0: b6f5e000 00100073 00000000 dcabc600 00000000 dcb59ba8 00000001 00000001
Message 1 of 6
CrimpOn
Sensei

Re: Orbi RBR40 kernel panics

Wow. First time I've seen THAT.  What firmware is on the Orbi?  Maybe this is a good time for a "Factory Reset" and configure from scratch.  If it is less than one year old, it should be under warranty.

I love my Orbi.
Message 2 of 6
FURRYe38
Guru

Re: Orbi RBR40 kernel panics

What is the Mfr and model# of the ISP modem the NG router is connected too?

 

Do you have RBS connected? Wireless or wired? 


@someuser2 wrote:

My Orbi RBR40 randomly reboots several times a day. The debug logs indicate that this is caused by a kernel panic:

<0>Kernel panic - not syncing: Fatal exception in interrupt
<4>@@@@@@@@@ DNI Kernel panic @@@@@@@@@@
3 <0>3ea0: b6f5e000 00100073 00000000 dcabc600 00000000 dcb59ba8 00000001 00000001

 

My Setup (Cable 1Gbps/50Mbps)>CAX80 v2.1.2.1(LAG Disabled)> RBK953(v6.0.3.68) & XR450(v130)
Additional NG HW: C7800/CM1100/CM1200CM2000, Orbi CBK40, CBR750, RBK853 v4.6.3.16(AP) & RBK752 v4.6.5.14, RBK50(v22), SXR30(v110), R7000(v34), R7800(v84), R7960P(v82), EX7500/EX7700, and WNHDE111
Message 3 of 6
someuser2
Aspirant

Re: Orbi RBR40 kernel panics

It is attached to a Surfboard 6141 modem. I tried a factory reset, but it did not make a difference. The panic occurs in a function related to neighbor advertisements (ecm_interface_send_neighbour_solicitation), so I tried disabling IPv6 a week ago - no reboot since (though this is just a workaround, of course; you'd expect a modern router to properly support IPv6). The panic log indicates that an alignment exception occurs when executing a LDREX instruction; I believe this occurs in atomic_dec_and_test in neigh_release (which is inlined in ecm_interface_send_neighbour_solicitation; this atomically decrements the reference count in the neighbour struct). I am not too familiar with ARMv7; does LDREX require a page-aligned pointer? If so, I think this is the cause - the refcnt member in struct neighbour is at offset 0x18, which isn't page-aligned. I can provide a full panic log for your engineers to look at.

Message 4 of 6
CrimpOn
Sensei

Re: Orbi RBR40 kernel panics

My guess is this is something that Netgear engineers would enjoy seeing. Alas, everyone on this community forum is a volunteer who happens to enjoy participating.  In two years, I have never had the impression that Netgear engineers monitor or participate in the myriad of user forums.  If the Orbi is still in the 90 days of "complimentary support", I urge you to file a support ticket directly with Netgear.  If you have had it more than 90 days, the best strategy is to interest one of the forum "moderators" in the problem.  Such as @Dustin_V or @Blanca_O 

I love my Orbi.
Message 5 of 6
FURRYe38
Guru

Re: Orbi RBR40 kernel panics

As suggested, please contact NG support and let them know whats is going on. Ask about an RMA. 


@someuser2 wrote:

It is attached to a Surfboard 6141 modem. I tried a factory reset, but it did not make a difference. The panic occurs in a function related to neighbor advertisements (ecm_interface_send_neighbour_solicitation), so I tried disabling IPv6 a week ago - no reboot since (though this is just a workaround, of course; you'd expect a modern router to properly support IPv6). The panic log indicates that an alignment exception occurs when executing a LDREX instruction; I believe this occurs in atomic_dec_and_test in neigh_release (which is inlined in ecm_interface_send_neighbour_solicitation; this atomically decrements the reference count in the neighbour struct). I am not too familiar with ARMv7; does LDREX require a page-aligned pointer? If so, I think this is the cause - the refcnt member in struct neighbour is at offset 0x18, which isn't page-aligned. I can provide a full panic log for your engineers to look at.


 

My Setup (Cable 1Gbps/50Mbps)>CAX80 v2.1.2.1(LAG Disabled)> RBK953(v6.0.3.68) & XR450(v130)
Additional NG HW: C7800/CM1100/CM1200CM2000, Orbi CBK40, CBR750, RBK853 v4.6.3.16(AP) & RBK752 v4.6.5.14, RBK50(v22), SXR30(v110), R7000(v34), R7800(v84), R7960P(v82), EX7500/EX7700, and WNHDE111
Message 6 of 6
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